Abstract Details
| Name: Debi Prasad Choudhary Affiliation: California State University Northridge Conference ID: ASI2018_1080 Title : Flows along Super-Penumbral Fibrils of Sunspots Authors and Co-Authors : Christian Beck National Solar Observatory, Boulder Abstract Type : Contributed Talk Abstract Category : Sun and the Solar System Abstract : Sunspots are the main ingredient of the solar cycle and the sites of its major eruptive events. Understanding the structure of these objects is an important aspect for studying our nearest star. We observed several sunspots using the Spectropolarimeter for Infrared and Optical Regions at the Dunn Solar Telescope during 29 July to 4 August 2013. The data consist of full Stokes profiles in the Ca II 854.2 nm and Fe I 1.56 micron lines. The inversion of these Stokes spectra provides the magnetic, thermal and velocity structure at photospheric and chromospheric heights of sunspots. In this paper, we present the results on the 3D thermal structure in the superÂpenumbral canopy of a round sunspot, derived by a novel approach for the inversion of Ca II IR spectra. Tracing individual fibrils in the superÂpenumbral canopy, we find that about half of them form only short loops of a a few Mm length that return to the photosphere in the close surroundings of the sunspot instead of connecting to more remote magnetic network at the outer end of the moat flow. We also find indications for standing shocks at the inner foot points of the flow channels that are compatible with a supersonic siphon flow scenario. |